We present experimental results on two-qubit Rydberg blockade quantum gatesand entanglement in a two-dimensional qubit array. Without post selectionagainst atom loss we achieve a Bell state fidelity of $0.73\pm 0.05$, thehighest value reported to date. The experiments are performed in an array ofsingle Cs atom qubits with a site to site spacing of $3.8 ~ \mu\rm m$. Usingthe standard protocol for a Rydberg blockade C$_Z$ gate together with singlequbit operations we create Bell states and measure their fidelity using parityoscillations. We analyze the role of AC Stark shifts that occur when usingtwo-photon Rydberg excitation and show how to tune experimental conditions foroptimal gate fidelity.
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机译：我们目前在二维量子比特阵列中对两个量子比特的Rydberg封锁量子门和纠缠的实验结果。在没有针对原子损失的事后选择的情况下，我们实现了$ 0.73 \ pm 0.05 $的贝尔状态保真度，这是迄今为止报道的最高价值。实验在单个Cs原子量子位的阵列中进行，其位点间距为$ 3.8〜\ mu \ rm m $。使用用于Rydberg封锁C $ _Z $门的标准协议以及单量子位运算，我们可以创建贝尔状态，并使用奇偶校验来测量其保真度。我们分析了使用双光子里德堡激发时发生的AC Stark移位的作用，并展示了如何调整实验条件以获得最佳的门极保真度。
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